找出下列三个句子应用什么语调。
①— What day is it today?
②— It's Thursday.
③— Then tomorrow will be Christmas Day.

A、①升调 ②降调 ③降调

B、①降调 ②升调 ③降调

C、①降调 ②降调 ③升调

D、①降调 ②降调 ③降调